Summary Aim To estimate the additional risk of venous thromboembolism (VTE) in men with prostate cancer compared to men without prostate cancer in Sweden. Design Nationwide cohort study following 92,105 men with prostate cancer and 466,241 men without prostate cancer (comparison cohort) matched 5:1 by year of birth and residential region. Ambit The general male population of Sweden (using the Swedish national prostate cancer database). Primary and secondary outcome measures Crude incidence ratio ratios (CPRs) comparing the incidence of VTE in men with prostate cancer and men in the comparison cohort. Cox regression was used to calculate VTE HRs adjusted for confounders. Results 2955 men with prostate cancer and 9774 men in the comparison cohort experienced a first VTE during a median follow-up of 4.5 years. Deep vein thrombosis (DVT) accounted for 52% of VTE cases in both cohorts. The median time from the start of follow-up to VTE was 2.5 years (IQR 0.9–4.7) in the prostate cancer cohort and 2.9 years (IQR 1.3–5.0 ) in the comparison cohort. Crude VTE incidence rates per 1000 person-years were 6.54 (95% CI 6.31 to 6.78) in the prostate cancer cohort (n = 2955 events) and 4.27 (95% CI 95%: 4.18 to 4.35) in the comparison cohort (n = 9774 events). The IPR decreased from 2.53 (95% CI: 2.26 to 2.83) at 6 months to 1.59 (95% CI: 1.52 to 1.67) at 5 years of follow-up. The adjusted HRs were 1.48 (95% CI: 1.39 to 1.57) for DVT and 1.47 (95% CI: 1.39 to 1.56) for pulmonary embolism after adjustment for the patient’s characteristics. Conclusions Swedish men with prostate cancer had a mean 50% increased risk of VTE during the 5 years after cancer diagnosis compared to matched men without prostate cancer. Clinicians should be aware of this marked increase in VTE risk in men with prostate cancer to help ensure timely diagnosis. |
Incidence proportion (%) of first VTE in men with prostate cancer and men without prostate cancer. IPR: incidence proportion ratio; VTE, venous thromboembolism.
Comments
New research published in the online journal BMJ Open suggests that men with prostate cancer have a 50% higher risk of developing serious, life-threatening blood clots within five years of being diagnosed with cancer compared to men with the same age without prostate cancer.
Although the risk level is lower than other forms of cancer, researchers encourage doctors to be alert to this risk to allow for timely diagnosis and treatment, should a blood clot occur.
This is important because venous thromboembolism (VTE), the type of blood clot in this study, is a leading cause of death among people with cancer, with a higher risk in those with more advanced disease.
Prostate cancer is the most frequently diagnosed cancer in middle-aged and older men, which means that many men with this type of cancer could experience a VTE.
People with cancer have a higher risk of developing venous thromboembolism (VTE), dangerous but treatable blood clots in the veins, than people without the disease, and the risk varies depending on the type of cancer and the stage at which it is found. VTEs are one of the leading causes of death in patients.
Prostate cancer is the cancer most commonly diagnosed in middle-aged and older men, meaning men with prostate cancer are at risk for VTE.
Some previous studies have suggested that the risk of VTE is two to three times higher in men with prostate cancer than among men of similar age without cancer.
However, researchers wanted more recent data in light of the dramatic improvement over the past decade in the way men with prostate cancer are managed. This includes widespread adoption of newer anticoagulant drugs for other conditions, but which could potentially lower the risk of VTE.
Therefore, a team of European researchers carried out a large-scale study using national data from men across Sweden, collected between 2007 and 2017, to compare the occurrence of VTE between 92,105 men with prostate cancer and 466,241 men of the same age without prostate cancer. cancer (the comparison group).
They found that 3.2% of men in the prostate cancer group experienced a VTE within five years of their cancer diagnosis, compared with 2.1% of men in the comparison group.
They estimated that out of every 1,000 men with prostate cancer, about seven would develop a VTE each year, compared with about four out of every 1,000 men without prostate cancer.
After taking into account factors that could affect VTE risk in their analysis (such as the presence of cardiovascular disease and socioeconomic factors), the researchers showed that men with prostate cancer had a 50% higher risk than those in the prostate cancer group. comparison over the five years. one-year study period, with the highest risk period being the first six months after cancer diagnosis.
Because this was an observational study, it is unclear how much of the increased risk was due to prostate cancer itself or to other differences between the two groups of men that could have affected the risk of VTE and that could not be controlled for. For example, a limitation of the study was the absence of information on smoking and alcohol intake.
However, this was a large study and the data sources used (several national registries) are known to be of good quality. The use of data from men across Sweden means the findings are likely to be an accurate reflection of VTE risk among those with and without prostate cancer.
The authors concluded: "The magnitude of the increased risk of VTE among men with prostate cancer observed in our study is smaller than that observed for other cancer types as observed in previous studies, and is likely attributable to the high proportion of men with localized disease and at low risk of cancer progression.
“Despite this, doctors treating men with prostate cancer should be aware of the markedly increased risk of VTE in these men, particularly in the first six months after cancer diagnosis, to help ensure timely diagnosis.” of VTE.”
The magnitude of the increased risk of VTE among men with prostate cancer observed in our study is smaller than that observed in other cancer types, as observed in previous studies, and is likely attributable to the high proportion of men with localized disease and low risk of cancer progression. Despite this, physicians treating men with prostate cancer should be aware of the markedly increased risk of VTE in these men, particularly in the first 6 months after cancer diagnosis , to help ensure timely diagnosis of TEV.
